Lifting-jack.



PATENTBD SEPT. 22, 1903.

No. 739,654. Y v

G. B'. DAVISON. LIP'I'ING JACK. APPLmATIoN Hmm 00T. 11, 1902.

Q4 TTORNE YS.

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WITNESSES:

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ivo. 739,654.

UNITED STAT-Es" Ilatented September 22,

PATENT' OFFICE.

enoacngnnnnrr DAvIsoN, or UrioA, New Yoan.

, Lvl FTlfNG-JACKL SPECIFICATION forming part of Letters PatentI N o.739,654, dated September 22, 1.903.

n Application i'lledOctoher 11,1902.k Serial No. 126.854.' (No model.) l

To all whom it may concern:

Be it known that I, GEORGE BENNETT DAVI- sON, of Utica, in the county ofOneida, in the State of New York, have invented new and; usefulImprovements in Lifting Jacks, of which the following, taken inconnection with' the accompanying drawings, is a full, clear, and exactdescription.

This invention relates to improvements in lifting-jacks, and refers moreparticularly to that class in which a hand-lever and gravityp'awls areemployed to control the operation of a suitable plunger, hereinafterdescribed.'

I have sought in this invention to produce a light, strong, and durablewagon-jack which may be readily carried in the hand from place to placeand which-is free from bolts or rivetsy and capable of'being readilyassembled or disassembled with a minimuml amount of labor and time.

To this end the invention consists in the combination,construction,-andlarrangement of the component parts of a lifting-jack,hereinafter fully described, and pointed out in the claims'. K l

Referring to the drawings, Figure l is a top plan of a lifting-jackembodying my invention. Fig. 2 isa side elevation, partly broken away,of the parts seen in Fig. 1. Fig. 3 is a transverse section taken online 3 of Fig.` 2. Figs; ai, 5, and 6 are perspective views showing,respectively, the lifting and holding pawls and the link employed fortransmitting motion from the operating-lever to,`

the lifting-pawl. Y

Similar reference characters indicate corresponding parts in all theviews. Y

In carrying out theobjects of my invention I employ a hollow uprightstandard 1, which is mounted upon suitable' supporting-legs 2, daringoutwardly and downwardly from the base of thehollow standardvl andunitedat their lower ends to a substantially flat baseplate 3, adaptedto rest upon'the'ground or other convenient support, the hollow standard1 being supported a considerable Adistance above the base-plate and isprovided with a lengthwise gnide-openinge for receiving areciprocally-movable lifting-plunger 5. The upper and lower ends of theguide-opening 4. are open, and the plunger 5 is movable through saidopen ends,- the guide-openjing being of sufficient length to affordample bearing forlthe plunger 5, and thecentral portion of the plungeris preferably reduced in .thickness,soas to form opposite lengthwisebearing faces or ribs 6 at opposite longitudinal edges of the plunger.This plunger is of substantially the same cross-sectional formthroughout its entire length, eX-

cept that the upper end is lslightly enlarged 4for forming a head''7,havinga substantially dat bearing-face 8. Thehead 7 and body of theplunger 5 are formed integral with each other, and the hollow standardl, legs 2, and base 3 are also cast together, the upper end 'of theupright standardl ibeingformed with an upwardly-projecting lug or ear 9,having a slot or ,opening l0, in which is movable a suitablegravity-pawl 11, the lug 9 being located at one side of the plunger, andthe lower edge of the slot or opening 10 serves as a fulcrum upon whichthe gravity-pawl 11 may be tilted for.Y releasing the plunger in amanner hereinafter described.

.The opposite 'outer faces` of the upright standard l'are formed withlugs 12, which Lare cast 'integral with the standard and form pivotalbearings for an operating-lever 13, the lugsv12 being disposed inproximity to the upper end of the standardv 1,' and the le ver, beingpivotally mounted upon `said-lugs, lis also arranged in I proximity tothe upper end of the standard and is adapted to rock vertically.` Thislever 13 preferably consists of 'a metallic head of malleable iron orvsimilar material, having one end bifurcated to receive the upper end ofthe standard l,

thereby forming oppositely-arranged arms 14,

.having their intermediate portions provided with apertures 15 forreceiving the lugs or Ybearings 12, said arms extendingtransverselybeyond the upright standardV and are provided with additional apertures16, in which is journaled a suitable link 17 for operating ialifting-paul 18.

The oppositeend of the metallic head of the operating-lever 13terminates in a hollow boss 19 for receiving a handle 20, said handlefitting in the socket of the hollow boss 19 and is readily removabletherefrom during transportation in order to economize in space andfacilitate the packing of the jacks in large quantities for storage orshipment.

ICO

rear faces of the -lifting-plunger 5.

The holding and lifting pawls 11 and 18 are preferably formed of cheapcast metal, such as malleable iron, and are provided with openings 2land 22 for receiving the plunger 5. These pawls are located betweentheupper end of the standard 1 and head 7 of the plunger 5, theholding-pawl 11 being located beneath the lifting-pawl 18 and isprovided with a linger-piece 23, cast integral therewith and extendingoutwardly and upwardly from the lug or ear 9, whereby the operator mayreadily engage the portion 23 and rock` the rear end of the pawlupwardly upon the fulcrum previously mentioned for releasing the samefrom engagement with the front and As previously stated, these pawls areformed Lfrom malleable iron or similar metal, and are therefore too softto stand the wear incidental to the frictional engagement of theopposite ends of their respective openings with the front and rear facesof the lifting-plunger 5. I therefore provide each of the pawls 11 and18 with a pair of nibs or biting-teeth 24, which consist of hardenedpins of different material from the pawls, such as hardened steel, whichare inserted through the walls of the openings in. such manner as toform the front and rear engaging faces of the openings in the pawls,which faces bite upon the opposite edges of the lifting-plunger as thelever is operated, the lifting-pawl serving to elevate the plunger ateach downward movement of the handle of the lever 13, and the pawl 1loperates to hold the plunger in its adjusted position.

The lifting-pawl18 projects beyond the rear edge of the plunger and isprovided with an additional opening 25 and suitable bearings 26 forreceiving the upper end of the link 17. This link 17 is formed at itslower end with pintles 26', cast integral therewith and inserted intothe openings 16, the upper end of said link being provided with bearings27, normally seated in the bearings 26, and is also provided with ahook-shaped extremity 28, projecting throughl and above the'opening 25and adapted to engage the rear wall of said opening to effect thepositive operation of the pawl18 and also to prevent its accidentaldisplacement from engagement with the link 17.

The end walls of the openings 21 and 22 in the pawls 1l and 18 arepreferably V-shaped, with theinapexes in close proximity to the oppositeedges of the lifting-plunger, and the nibs or pins 24 are insertedthrough the apexes of these end walls, so as to project inwardlyslightly beyond these apexes, so as to insure their engagement with thefront and rear edges of the lifting-plunger.'

It is apparent from the foregoing description that the pawls 11 and 18are fulcrumed respectively upon the lug 9, bearings 27 at opposite sidesof the lifting-plunger, and that their ends, which engage thelifting-plunger, are free to drop by gravity, and therefore tend toimpinge their nibs against the opposite faces of the lifting-plunger,this tendency in the lifting-pawl serving to lift the plunger when thehandle 2O is depressed, and the nibs of the pawl 11 also bite upon theopposite edges of the plunger and prevent further downward movementthereof. 1

When it is desired to lower the liftingplunger gradually, the operatorsimply engages the portion 23 and rocks the inner end of the pawlupwardly, and at the same time, having a firm grip upon the handle 20,permits the plunger to gradually descend.

In assembling the lever upon the studs 12 and pintles 26 the arms 14 arespread a sufficient distance to receive the studs and pintles for thepurpose of'alining the same with their respective apertures in the arms12, whereupon said arms are drawn or forced toward each other, and theparts are thus positively connected or assembled.

The holding-pawl 11 is provided with laterally-projecting lugs 30,depending from its lower face and projecting into the path of the lever13, so that when it is desired to lower the plunger instantly it issim-ply necessary to rock the lever until the upper faces of the arms 14engage the lugs 30 and elevate the pawl, whereupon the lifting-plungerdrops to its lower limit.

Having thus fully described my invention, what I claim, and desire tosecure by Letters Patent, is

1. A lifting-jack comprising a hollow upright standard,a lifting-plungerguided on the standard, a lever fulcrumed on the upper end of thestandard and extending to opposite sides thereof, a holding-pawlfulcrumed on the standard above and at one side of the lever-fulcrum, alink pivotally mounted on the lever at the other side of the fulcrum andrising therefrom, and a lifting-pawl fulcrumed on the upper end of thelink above the holding-pawl and engaging the lifting-plunger for thepurpose described.

2. In a lifting-jack, the combination of an upright standard having alengthwise openin'gfa lifting-plunger guided in said opening, a levermounted on the standard and extending to opposite sides thereof andhaving a handle at one end, a link pivotally mounted on the other end ofthe lever and rising therefrom, a lifting-pawl fulcrumed on the upperend of the link above the lever, and the hold- IOC IIO

ing-pawl fulcrumed on the standard above end of the link above thelever, a gravity holding-pawl fulcrumed on the standard and interposedbetween the upper end of the standard and the lifting-pawl, and providedwith a finger-piece, for the purpose set forth;

4. In a lifting-jack, the combination with an upright standard formed ofcast metal and .having bearings cast on its opposite faces, aleverhaving a bifu mated extremity, the arms of which are flexible andperforated to receive said bearings, a plunger guided on the Y standard,a link mounted between said arms, a lifting-pawl mounted on the link andprovided with-xlibs for engaging opposite faces

